Our research objectives comprise a multifaceted approach to the problems of influenza and the antigenic variation of the causative virus. In this study of the "Biology and biochemistry of influenza viruses," specific objectives during the current year have included: 1) continued research on the development of influenza vaccines; 2) genotypic characterization of influenza viruses on the basis of RNA migration patterns on polyacrylamide gels, and 3) continued study of cellular immunity in influenza in a mouse model system. The studies of vaccine development are obviously directly related to efforts to control human influenza. The studies of influenza virus RNA gel patterns have also received immediate and direct application to such practical problems as definition of the genes in the present recombinant swine vaccine virus and definition of the genotype of the potentially pandemic NJ/swine virus. This method is an enormously powerful tool for future epidemiologic studies and also for definition of genes responsible for viral virulence. The studies of cell mediated immunity in the mouse model can be expected to shed light on the pathogenesis of the human disease. Our research goals include: further investigations of neuraminidase-specific artificial immunization, particularly with isolated purified neuraminidase antigen, 2) application of the RNA methodology to studies of the genetic basis for influenza viral virulence and for epidemiologic investigations relating to the origin of pandemic viruses, and 3) continued studies of cell mediated immunity.